How to bleed a radiator – a guide from CW Services Plumbing and Heating

With continued use, central heating systems that incorporate radiators will accumulate air in the pipe-work, and this often results in radiators being partially or completely blocked and not heating up properly. It’s a very common problem, and one which you can easily remedy yourself by what is referred to as bleeding the radiators.

Knowing how to do this will save you having to call in a plumber; but if the blockage persists after bleeding, and you live in the South London area, a quick call to CW Plumbing and Heating Services is the next step. Nine times out of ten, the simple bleeding procedure which we are about to explain, will sort out the problem by removing any pockets of air that might have built up, after which your radiators should perform effectively and efficiently.

Bleeding your radiators – Step 1

First things first; turn the central heating system on. Having done this, you will then need to wait a few minutes until all of the radiators heat-up.

Bleeding your radiators – Step 2

The next job is to identify which radiators require bleeding. To do this, visit all radiators in the central heating system, and feel all parts of each radiator to identify any potential cool or cold spots. Before you start touching the radiators, just be careful not to burn your hands. If necessary wear a pair of thin cotton gloves.

If you do find any cool spots on a radiator, it means that it needs bleeding to release the trapped air.

Bleeding your radiators – Step 3

Before commencing the bleeding operation, you should turn the central heating system off. This will ensure that the radiators are cool enough to handle.

There are two ways of potentially bleeding radiators, depending on the type you have installed. Some of the more modern radiators can be bled using a screwdriver. However, the majority of radiators will require a radiator key. If you haven’t got one, you can buy a radiator key from your local plumbing or DIY centre. They are inexpensive.

Bleeding your radiators – Step 4

Before you start to bleed a radiator, make sure you have a cloth prepared. This is just to catch any water that will stream out once the air has been bled.

  • Attach the key or screwdriver to the screw or square spigot in the radiator valve.
  • Holding your cloth immediately under the spigot or screw, turn the key or screwdriver anticlockwise gently.
  • If any air is trapped you will hear it hiss as it is released. One the air is released, a thin jet a water will steam out, which you can catch with your cloth.
  • As soon as the jet of water appears, quickly shot off the valve.

Bleeding your radiators – Step 5

Once you’ve been around all radiators and bled them where necessary, you should then turn your central heating back on, and check that the pressure the pressure gauge on your boiler is normal.

Getting in touch with CW Services Plumbing and Heating if necessary

The radiator bleeding process is a simple one, but if you do run into any problems, or the system is still not working correctly once you’ve finished, call CW Services Plumbing and Heating on 020 7733 6812, or 07949 095 184.